double blow or crippler?

So I know it's kind of a weird question but I'm not going into the pvp skills and eagle eye isn't worth it right now(at least imo) so my question is I have 5 points level and not 100% positive where these should go. I could go into acc passive but I don't believe that's worth it so my options are double blow or crippler. I could easily change the dps on each skill if I know the damage per point difference(or of they scale linearly per point or not) but I don't so my question is leave crippler at rank 5 and up double blow to 6 or leave double blow t 1 and up crippler to 10?

Depends, what are you looking for? Burst damage or DPS?
Double Blow has 2sec cooldown so would give you more DPS in the long run.
Crippler does a big hit (burst), and has a high ch-atk added aswell, but comes with a very long cooldown (9seconds).

Cripler can hit roughly as hard as slaughter when maxxed (if you are wearing full envoy/sorcerer/seer), and that is every 9 seconds. The skill also grabs aggro (the description about decreasing aggro is wrong. It increases it.)

It does well for PVP and PVE.

Double blow scales terribly. It's not really that great for DPS....just put 1 point in it and use it as a space-filler.

If you're wanting to win a DPS race, you want a lot of burst damage. If you can get burst damage over and over very quickly, however, you can do wonders on DPS. That is where cripler comes in to play.

1. Go to a dungeon with the exactly same team for 2 runs.
2. First run: full invest at double blow
3. Note your results at the end of last boss. Print screen it, so you don't have to use papers, excel sheets or whatsoever.
4. Out from dungeon: Reset skills, go for full invest for Crippler. Don't forget to ask your team to wait for you to reset and setting skills on shortcuts.
5. Second run: Then do point 3 again.
6. You will got results: Crippler is best overall burst damage and DPS.

I did this on my SW: ValkyrieClaw (RG).

My recomendation: 5 points on Crippler; 0 for Double Blow.

Summaries:
Crippler works best for PvP too, not only PvE.

To get the best steady team for experiment, you can ask regular active players on your guild.
Or if you are OP player, you just need to "borrow" a party. (asking someone to party you, and then you go to the dungeon alone until your experiment completed).

On PvE negative notes, Crippler has long duration cool down (9 secs). You will "feel" clumsy when all of your skills are on cooling down state. But don't worry, it is not your style which determine you are good or not, but your rank on DPS board will do.

To use a balance of Double Blow and Crippler is not recommended. When you did the experiment, you will find: Full Crippler wins the highest DPS amount compared to Double Blow, or a set of balance between those two.

To get factual result; doing an experiment is a must, not only calculator based logical conclusion. There are a lot of factors out there which influence the outcome produced. (opponent DEF, VOID, element resist, your balancing actions to refill HP/SP, cooling down state, buffs, de-buffs, etc.)
There are a lot of facts you will get which give contrary results against calculator based logical mind set.

After you got your results; I would like to recommend you to use: seer/envoy for earrings, scout/killer for necklace and trinket, and then seer/envoy for rings. That will make more difference on your crippler (and all other skills).